How to write a good ASP application

Program

How to create robust, accurate, maintainable, and performance-Good ASP applications? What do you want to do? Not doing what? In this paper, the main check-points (check point) is given in the form of outline.

What is ASP

Active Server Page, abbreviated as ASP, is:

L Connect user Interface (HTML) and business logic (Business Logic);

• Provide consistent, easy-to-use, stateful, web-based clients;

• Provide an application environment for Web applications that require transactional processing.

ASP is not:

• Where business logic is implemented (Business Logic); Business logic should be implemented through COM +, MTS, or the database.

Users of ASPs should have the following lessons:

• Develop applications, rather than developing an orphaned ASP page;

• Caching of inputs and outputs;

• test before release;

L Selective and good components;

• Reduce access to the database: The result of a cached transformation;

• Use of MSMQ to handle work with time delays;

Site design
What do you want to provide for your site?

U Information Architecture: 80/20 guidelines;

U site navigation;

U page layout;

U usability;

N use alt and title attributes;

n Do not use the image or image map navigation;

You are suitable for most of the lower-version browsers, considering their support for ActiveX, RDS, XML, DHTML, Java applets;

U screen resolution and number of screen colors

Does n support WebTV, PDA ...?

n Sets the width and Height properties of the IMG.

U non-browser access, such as Automatic Robot (Spider);

U using frames (frame)?

u use cookies for personalization;

U avoid bad connections;

u use META tags;

U content audit;

U content search;

U results Feedback: User feedback and tracking;

u reduce download time;

Three-layer, four-storey application design

Readability, maintainability
u use annotations;

u use <%option explicit%>; in VBScript scripts

U Store SQL strings using string variables: Easy to debug;

u use Server.MapPath and relative paths;

u use Adodb.inc or <!-metadata typelib=somelib file=somedll--> to refer to constants instead of using constant values directly.

U Specify the default parameters of ADO calls to avoid errors;

U use libraries or parts to encapsulate code.

The right approach:

u use Server.URLEncode

U error capture and handling

Internationalization:

u use <%CodePage%>

u use Session.CodePage

U in IIS5.0, Response.Write support UTF8

Other:

U reuse code with #include

U Use paging technology

Site Security:

U Customer Authentication

U Input Validation

U #include file do not use. Inc suffix, use. ASP or settings. Inc Application Mappings

U store MDB files in a non-web path;

U do security management with ADSI

Session and Application Status
Use of Session:

U is very convenient to use but very problematic;

U HTTP is a stateless protocol;

U design Shopping carts are particularly useful;

U is not conducive to scalability design (scalability);

u use <%EnableSessionState=false%> in pages that do not require session

U avoid using session as completely as possible;

U is not suitable for multiple Web server situations;

U some parts enable session to run in a single threading mode, reducing throughput;

u consumes memory;

U session has timeout problem

You need the client's browser to open cookie settings;

U do not save the recordset in the session, or cache the connection object;

u do not use empty session_onend in Global.asa;

U option:

n Cookies

U Direct State code: Simple, easy, unsafe

U back-end Database ID as status value

N QueryString Parameter

n like Amazon's URL way

N Hidden Forms

Application variable:

U Share variables

U cannot be saved persistently

U no more than one Web server, unless you are only a read-only variable.

Cache
U is ideal for static content

u do not use response.expires=0, use negative numbers:

n response.expires=-10000;

n Response.AddHeader "Pragma", "No-cache"

Uresponse.addheader "Cache-control", "No-store"

U Server Cache

U Proxy Cache

U Client Cache

Parts
U performance

U Scalability

U Split business logic and page performance

U is reused by ASP or other environment

U transaction Processing

U type safety

U Access Operating system features

U Protect intellectual Property rights

u use Server.CreateObject in the following situations:

N MTS Transaction Processing

N Context Security

n ASP Internal Parts

N OnStartPage, OnEndPage

u use <object runat=server> Delay object Initialization

Do you want to save to the session or application variable

U

Performance
n Response Buffer: response.buffer=true

N Close Connection and: Set connection=nothing

n using local Variables

N Replace Server.CreateObject with <object >

n do not use session and application variables

n Do not store COM objects in session or application variables

n Turn off script debugging

n Avoid repeating string additions

n Use response.isclientconnected at the top of a time-consuming page

N Using MSMQ

n Do not store large arrays in session or application

n Do not ReDim arrays

n assigns an object of a collection type to a temporary variable

n Reduce the maximum number of threads in the microprocessor (run Regedt32, hkey_local_machine\system\ currentcontrolset\services\w3svc\asp\parameters, Increase the ProcessorThreadMax, reduce the value, see the performance change, or increase the value. )

n Sets the AspScriptEngineCacheMax so that it equals the number of processorthreadmax*cpu. The default is 30; (Under the System path: \system32\inetsrv/adminisamples, type adsutil.vbs, set/w3svc/aspscriptenginecachemax);

n Reduce session.timeout;

N in MMC, set the ASP application buffering to be valid.

To give some work to the client:

N CSS, DHTML

N XML

N RDS

n Remote Scripting

N Xmlhttp

N Client-side validation

n Reduce File size

N Avoid HTTPS and SSL whenever possible

N Test Performance using Response.End

N

Database
n Reduce access to database access;

n the result of the buffer transformation;

n Use ODBC connection pooling and OLE DB resource pools;

n Use System DSN or non-DSN, do not use DSN or file DSN;

n makes ADO run in dual-threading mode (both-threaded): Makefre.bat;

n Use the Field object of ADO;

n GetString or GetRows relatively fast;

n rds and XML to marry the load to the client;

n Do not use SELECT *, write the fields out;

n Use SQL Server 7 as much as possible and do not use access;

n Use SQL Server features: stored procedure, Job, Join, sort, group

n Use SQL analysis to optimize SQL performance

N Using indexes

n Use name-pipes locally, use sockets remotely

N precisely specifies the command Type

New features of IIS 5
n A reliable reboot

N ASP Performance Improvement

n Server.Transfer better than Server.redirect

N Server.Execute

N Server.GetLastError